From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
From: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
commit d0bd52c591a1070c54dc428e926660eb4f981099 upstream.
Commit b102f0c522cf6 ("mt76: fix array overflow on receiving too many
fragments for a packet") fixes a possible OOB access but it introduces a
memory leak since the pending frame is not released to page_frag_cache
if the frag array of skb_shared_info is full. Commit 93a1d4791c10
("mt76: dma: fix a possible memory leak in mt76_add_fragment()") fixes
the issue but does not free the truncated skb that is forwarded to
mac80211 layer. Fix the leftover issue discarding even truncated skbs.
Fixes: 93a1d4791c10 ("mt76: dma: fix a possible memory leak in mt76_add_fragment()")
Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/a03166fcc8214644333c68674a781836e0f57576.1612697217.git.lorenzo@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/mediatek/mt76/dma.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -395,13 +395,13 @@ mt76_add_fragment(struct mt76_dev *dev,
{
struct sk_buff *skb = q->rx_head;
struct skb_shared_info *shinfo = skb_shinfo(skb);
+ int nr_frags = shinfo->nr_frags;
- if (shinfo->nr_frags < ARRAY_SIZE(shinfo->frags)) {
+ if (nr_frags < ARRAY_SIZE(shinfo->frags)) {
struct page *page = virt_to_head_page(data);
int offset = data - page_address(page) + q->buf_offset;
- skb_add_rx_frag(skb, shinfo->nr_frags, page, offset, len,
- q->buf_size);
+ skb_add_rx_frag(skb, nr_frags, page, offset, len, q->buf_size);
} else {
skb_free_frag(data);
}
@@ -410,7 +410,10 @@ mt76_add_fragment(struct mt76_dev *dev,
return;
q->rx_head = NULL;
- dev->drv->rx_skb(dev, q - dev->q_rx, skb);
+ if (nr_frags < ARRAY_SIZE(shinfo->frags))
+ dev->drv->rx_skb(dev, q - dev->q_rx, skb);
+ else
+ dev_kfree_skb(skb);
}
static int
